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From | brendan.halpin@ul.ie (Brendan Halpin) |
To | statalist@hsphsun2.harvard.edu |
Subject | Re: st: score test for the parallel regression assumption |
Date | Tue, 22 May 2012 16:45:14 +0100 |
On Tue, May 22 2012, Thomas VanHeuvelen wrote: > Does anyone know of a way to perform a score test for the parallel > regression assumption after running an ordered logistic regression command > (e.g. ologit or gologit2)? More specifically, is anyone aware of a > program/procedure in Stata that can reproduce the score test given by > SAS's -proc logistic- command? I don't know what the score test is, but does the Brant test do what you want? It's part of Long & Freese's -spostado- (-findit spostado- to get the details). Example: . xi: ologit ropfamr i.rsex rage i.rsex _Irsex_1-2 (naturally coded; _Irsex_1 omitted) Iteration 0: log likelihood = -18924.158 Iteration 1: log likelihood = -17818.231 Iteration 2: log likelihood = -17802.121 Iteration 3: log likelihood = -17802.088 Iteration 4: log likelihood = -17802.088 Ordered logistic regression Number of obs = 12725 LR chi2(2) = 2244.14 Prob > chi2 = 0.0000 Log likelihood = -17802.088 Pseudo R2 = 0.0593 ------------------------------------------------------------------------------ ropfamr | Coef. Std. Err. z P>|z| [95% Conf. Interval] -------------+---------------------------------------------------------------- _Irsex_2 | .8339045 .033062 25.22 0.000 .7691041 .8987048 rage | -.0371618 .0009172 -40.51 0.000 -.0389595 -.035364 -------------+---------------------------------------------------------------- /cut1 | -3.833869 .0597563 -3.950989 -3.716749 /cut2 | -2.913506 .0547271 -3.02077 -2.806243 /cut3 | -1.132863 .0488522 -1.228612 -1.037115 /cut4 | .3371151 .0482232 .2425994 .4316307 ------------------------------------------------------------------------------ . brant, detail Estimated coefficients from j-1 binary regressions y>1 y>2 y>3 y>4 _Irsex_2 1.0198492 .91316651 .76176797 .8150246 rage -.02716537 -.03064454 -.03652048 -.04571137 _cons 3.2067856 2.5225826 1.1214759 -.00985108 Brant Test of Parallel Regression Assumption Variable | chi2 p>chi2 df -------------+-------------------------- All | 101.13 0.000 6 -------------+-------------------------- _Irsex_2 | 15.88 0.001 3 rage | 81.07 0.000 3 ---------------------------------------- A significant test statistic provides evidence that the parallel regression assumption has been violated. Regards, Brendan -- Brendan Halpin, Department of Sociology, University of Limerick, Ireland Tel: w +353-61-213147 f +353-61-202569 h +353-61-338562; Room F1-009 x 3147 mailto:brendan.halpin@ul.ie ULSociology on Facebook: http://on.fb.me/fjIK9t http://teaching.sociology.ul.ie/bhalpin/wordpress twitter:@ULSociology * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/